We will start the 2012 Field Season in late July. Until then, we do not expect much news.

Project Overview: This project, funded by the
LDEO Climate Center and The National Geographic Society, and
the National Science Foundation will secure
paleoclimate data necessary to place the rise and fall of the Great Mongol Empire in an annual, climatic context. Longstanding
speculation is that drought during the 13th century was a major driver in leading the Mongols to conquer Asia and Eastern Europe.
Our preliminary record indicates the opposite: the rise of the Mongols occurred during an extended, warm and wet pluvial. We
hypothesize that this climatic optimum led to high grassland productivity and that could have enabled Mongol expansion. Please note,
we do not think the rise of the Mongol Empire to be solelyclimatically deterministic. Many factors are involved with cultural expansion
and decline. However, we will soon have the data to investigate the potential role of climate. To test this hypothesis, we will
reconstruct drought and grassland productivity, the basis of energy and carrying capacity for the Mongolian herding culture, over the last 2k years.
However, due to ecotourism and wildfire pressures, it is urgent that we complete collection of this record before it is destroyed.

An ancient Siberian pine. Photo: N. Pederson

Background:
Chinggis Khaan's (Ghengis Khan) Great Mongol Empire, centered on the Orkhon Valley, was the largest land empire in world history.
At the time of Chinggis' death, the empire stretched from the Pacific Ocean to the Caspian Sea and northern Persia (Fig 1).
The empire continued to expand such that Mongolians controlled or influenced areas from the Hungarian grasslands to Vietnam, Syria,
Bagdad and Japan by the end of the 1200s. The extent of the Mongol Empire and the range of landscapes and cultures that fell under
this empire are unrivaled. The impact of Chinggis Khaan's adaptive, merit-based leadership still influences today's world
(Weatherford, 2004) and that he was one of the world's greatest leaders.

Figure 1 - The Mongol Empire (shaded portion of Eurasia) at 1227 CE, the time of Chinggis Khaan's death.

Questions still linger, however, as to how nomadic tribes from cold, arid Mongolia could conquer the agricultural societies of China
and eastern Europe: "Did a favorable climate provide an energetic base conducive to Mongolian expansion?" Also, "Did a
deteriorating climate lead to Mongol contraction?" Until now, no drought data existed to help address these questions.

Following our serendipitous discovery of ancient, subfossil wood from near the Orkhon Valley, we now have the first opportunity to
answer these questions through the development of an annually-resolved, drought record covering the Common Era (CE). Despite having
had the time to only sample 17 Siberian pine (Pinus sibirica), including just 7 subfossil samples, our record dates to back
658 CE. Because we were investigating fire history, we sampled only ~2
km2 in <4 hrs. Ultimately, the new record will allow for the creation a complete context of annual climatic in the rise and fall of
the Mongol Empire with the use an existing TRL temperature record in
central Mongolia (D'arrigo et al., 2001).

Historians have suggested that variable climate and drought drove the Mongol armies to raid eastern European farmers (Lattimore, 1938)
- our preliminary results directly contradict this speculation. Rather, it appears that climatic conditions ideal for grassland
productivity coincided with expansion of the Mongolian Empire. Data collected through this proposal will allow us to test the
hypothesis that a climatic optimum led to high grassland productivity and aided Mongol expansion.